This application incorporates by reference Japanese application Ser. No. P11-341188, filed Nov. 30, 1999, P11-341189, filed Nov. 30, 1999, and 11-341190, filed Nov. 30, 1999.
1. Field of the Invention
The present invention relates to a plug structure. More particularly, the present invention relates to a plug structure for a liquid container, such as a thermos bottle.
2. Description of the Related Art
In general, a portable liquid container, such as a water bottle or a thermos bottle, usually comprises a plug structure installed onto the upper opening of the liquid container for cutting off water and providing passages to pour or remove liquid. Recently, a newer plug structure that doesn""t have to be removed before pouring or removing liquid has been widely used. For example, a so-called one-touch plug has been disclosed for such purpose and function by a Japanese Patent Laid-open Publication No. 9-215610. The one-touch plug comprises a plug member composed of an inner cylinder and an outer cylinder, a valve guide, a valve and a flap. The plug member has a liquid passage that is formed between the inner and the outer cylinders for connecting a liquid outlet formed on the top end of the inner cylinder and a liquid inlet formed on the bottom end of the outer cylinder. The valve guide can be moved up and down by pushing a button installed on the plug member. The valve is installed on the front end of the valve guide for opening and closing the liquid inlet of the liquid passage. The flap is connected to the button and is synchronized with the valve for opening and closing the liquid outlet of the liquid passage. The one-touch plug further comprises a water cut-off mechanism, which has a seal member installed on the bottom end of the outer cylinder to seal the top of the valve, thereby the liquid inlet of the liquid passage is sealed.
The water cut-off mechanism mentioned above is formed only on a position where the liquid inlet locates and the required water cut-off location is widely spread. Therefore the pressure acted on the water cut-off location is not uniform if one of the parts, such as the bottom of the outer cylinder, the sealed member, or the valve are tilted or distorted. Additionally, when the plug is closed after finishing pouring liquid to the container, a little liquid remains along the liquid passage, and the residue liquid leaks from a gap between the flap, and the liquid outlet. For solving the problem as mentioned above, a Japanese Patent Laid-open Publication, JP 11-155745, discloses a plug structure where another sealed member is formed on the flap or the liquid outlet, by which both the liquid inlet and outlet can prevent liquid from leakage.
However, because the liquid outlet on the inner cylinder and the liquid inlet on the outer cylinder are formed individually, the liquid passage structure becomes complex so that it is hard to completely clean up the liquid passage.
In addition, because the movements of the valve for opening or closing the liquid passage utilize a push button formed on the plug member, the mechanism for opening and closing operation is vertically performed, causing the overall height of the plug to become higher. Furthermore, when the liquid passage is opened, the valve is moved into the liquid container. Because the temperature in the liquid container is higher than outside, the pressure in the liquid container is higher than outside, and therefore a larger force is required for opening the liquid passage.
However, the proposed structure is complex and costly. In addition, because the liquid is cut off from the bottom of the liquid inlet and from the top of the outlet, the cut-off pressures acted on the liquid inlet and outlet must be the same but it is difficult to adjust. Moreover, because the valve will move downwards when the plug is opened, when hot water is poured into the container, the vapor due to the hot water causes the pressure in the container to be higher than the outside environment, and thus it requires a larger force to open the plug.
Accordingly, it is an object of the invention to provide a plug structure for a liquid container, such as a water bottle or a thermos bottle, capable of easily cleaning up a liquid passage of the plug structure.
It is another object of the invention to provide a plug structure for a liquid container such that the overall height of the plug structure can be reduced and the open and close operation of the plug structure can be eased.
It is still another object of the invention to provide a plug structure for a liquid container such that a simple water cut-off structure is used for preventing the liquid inlet and outlet from leakage.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a plug structure for a liquid container, comprising an outer plug, an inner plug and a fixing device. The outer plug is substantially a cylinder shape with a bottom wall and detachably installed onto a liquid container, wherein the bottom wall is tilted, and a liquid passage hole, and an air hole are penetrated through the bottom wall and are respectively located on a lower position and a higher position of the bottom wall. A liquid passage is formed between the bottom wall and an upper opening of the outer plug body. The inner plug is pivotally connected to the outer plug through a hinge for opening or closing the outer plug, wherein the inner plug further comprises seal members thereon for sealing the liquid passage hole and the air hole respectively. The fixing device is used for securing the inner plug onto the outer plug, wherein the fixing device is installed on the inner plug, and moved back and forth on the inner plug.
The invention further provides a plug for a liquid container, comprising an outer plug, an inner plug, and a fixing device. The outer plug is substantially a cylinder shape with a bottom wall, and detachably installed onto a liquid container, wherein a liquid passage hole is penetrated through the bottom wall, and a liquid passage is formed between the bottom wall and an upper opening of the outer plug body. The inner plug is pivotally connected to the outer plug through a hinge for opening or closing the outer plug, wherein the inner plug further comprises a seal member thereon for sealing the liquid passage hole. The fixing device is used for securing the inner plug onto the outer plug, wherein the fixing device protrudes from a sidewall of the inner plug, and has a fixing claw for fixing the inner plug to an inner wall of the outer plug, wherein the fixing device is formed on the inner plug and moved back and forth along a protrusion direction of the fixing claw.
The invention also provides a plug for a liquid container, comprising an outer plug, an inner plug, and a fixing device. The outer plug is substantially a cylinder shape with a bottom wall and detachably installed onto a liquid container, wherein a liquid passage hole is penetrated through the bottom wall, and a liquid passage is formed between the bottom wall, and an upper opening of the outer plug body. The inner plug is pivotally connected to the outer plug through a hinge for opening or closing the outer plug, wherein the inner plug further comprises a liquid inlet seal member for sealing the liquid passage hole, and a liquid outlet seal member for sealing an inner wall near the upper opening of the outer plug. The fixing device is used for fixing the inner plug onto the outer plug. In addition, a hole is located between the liquid inlet seal member, and the inner plug, such that the hole is connected to the outside of the plug.